Compounds containing quaternary ammonium and methylenephosphonic acid groups

ABSTRACT

Compounds having improved properties of inhibiting the precipitation of metal ions when used in threshold amounts have been made which are derivatives of ammonia or di- or polyamines in which the amine hydrogens have been substituted with both methylenephosphonic acid groups or their salts and hydroxypropyl quaternaryammonium halide groups. Thus, ammonia can have two hydrogens replaced with methylenephosphonic groups while the third is replaced with a hydroxypropyltrimethylammonium chloride group; and three hydrogens of ethylenediamine can be replaced with methylenephosphonic groups, the fourth being replaced with a hydroxypropyltrimethylammonium chloride group.

BACKGROUND OF THE INVENTION

The use of methylenephosphonic acid substituted alkylene polyamines formetal ion control at less than stoichiometric amounts was suggested in apatent to Bersworth (U.S. Pat. No. 2,609,390) in 1952. Later a waterdispersible polymeric amine chelating agent which included alkylenephosphonate derivatives was indicated as having "threshold" effects inscale inhibition applications (see U.S. Pat. No. 3,331,773), this termbeing used to describe the use of the agent in less than stoichiometricamounts. The diamine and polyamine methylenephosphonate derivatives aretaught and claimed in U.S. Pat. Nos. 3,336,221 and 3,434,969,respectively. Some of the products disclosed in these two patents areavailable commercially and are recommended as scale inhibitors whenapplied in threshold amounts.

Some other patents disclose heterocyclic nitrogen containing compoundswhich are useful as chelating agents and may be employed in thresholdamounts are U.S. Pat. Nos. 3,674,804; 3,720,498; 3,743,603; 3,859,211;and 3,954,761.

Methylenephosphonates of polyalkylene polyamines, disclosed in U.S. Pat.No. 4,051,110, are made by reacting di- or polyamines with a chainextending agent such as a dihalide or an epoxyhalide, e.g. ethylenedichloride or epichlorohydrin and thereafter, with phosphorus acid andformaldehyde. Thus, for example, triethylenetetramine is reached withepichlorohydrin in an approximately one to one mole ratio; thereafterthe product is reacted with phosphorous acid, and formaldehyde in thepresence of hydrochloric acid. The resulting methylenephosphonatedpolyamine is useful in small amounts as a scale inhibitor, beingemployed at concentrations of 20-50 ppm.

Certain phosphonic acid derivatives of the aliphatic acids can beprepared by reacting phosphorous acid with acid anhydrides or acidchlorides, e.g. the anhydrides or chlorides of acetic, propionic andvaleric acids. The compounds prepared have the formula ##STR1## whereinR is a lower alkyl radical having 1 to 5 carbon atoms. The method ofmaking and using these products is described in U.S. Pat. No. 3,214,454.The use of threshold amounts to prevent calcium precipitation isdisclosed and claimed therein.

Compounds such as the reaction product of a halohydrin, e.g.epichlorohydrin, with an amine, e.g. trimethylamine, give quaternaryammonium chlorohydrin adducts, which have biological activity. Thechlorine of the chlorohydrin moiety can, of course, be reacted withanother amine to give a hydroxyalkyl quaternary ammonium compound andadduct of the amine.

It has now been discovered that such a functionality when attached to adiamine or polyamine which also contains a methylenephosphonic acidgroup will give a compound having improved threshold activity, i.e.inhibits precipitation of metal ions from solution at less thanstoichiometric amounts.

SUMMARY OF THE INVENTION

Compounds having improved properties of inhibiting the precipitation ofmetal ions when used in threshold amounts have been made which arederivatives of ammonia or di- or polyamines in which the amine hydrogenshave been substituted with both methylenephosphonic acid groups or theirsalts and hydroxypropyl quaternaryammonium halide groups. Thesecompounds have the formula ##STR2## wherein A, B, C and D substituentsare independently selected from hydrogen, methylenephosphonic acid, orsalts thereof, hydroxypropyltrialkylammonium halide, wherein thetrialkylammonium moiety contains alkyl groups having from 1 to 5 carbonatoms and n is 0 to 15, and wherein said substituents include at leastone methylenephosphonic acid group, or salt thereof, and at least onehydroxypropyltrialkylammonium halide group.

DETAILED DESCRIPTION OF THE INVENTION

The compounds of the present invention are substituted amines in whichat least one of the amine hydrogens is substituted with amethylenephosphonic acid group or salts thereof and at least one with aquaternary ammonium radical.

The following examples are representative of making the compounds of theinvention and of making the completely phosphonated compounds forcomparison.

EXAMPLE 1

Ethylenediamine (EDA) (15 g, 0.25 mole) and 94 g (0.25 mole) of a 50%aqueous solution of 3-chloro-2-hydroxypropyltrimethylammonium chloridewere added to a 500 ml round-bottom reaction flask equipped with awater-cooled reflux condenser, mechanical stirrer, thermometer with atemperature controller, and an addition funnel. The reaction mixture washeated to 90° C. and digested for about one hour and cooled.

Approximately 60 g of concentrated hydrochloric acid solution and 67.5 g(0.82 mole) of phosphorus acid were added to the reaction flask andheated to reflux and maintained for one hour. Aqueous 37% formaldehydesolution (67.4 g, 0.83 mole) was weighed into the addition funnel andadded over a two-hour period. The reaction mixture was heated at refluxfor an additional three hours and then cooled. The product was thederivative of EDA in which one hydrogen had been replaced with2-hydroxypropyltrimethylammonium chloride groups and the remaininghydrogens with methylenephosphonic acid groups.

EXAMPLE 2 (Comparative)

Ethyleneamine E-100* (12.5 g) and 12.5 g of deionized water were addedto a 500-ml round-bottom reaction flask equipped as described inExample 1. Approximately 110 g of concentrated hydrochloric acidsolution and 31.1 g (0.38 mole) of phosphorous acid were added to thereaction flask and heated to reflux and maintained for one hour. Aqueous37% formaldehyde solution (26.8 g, 0.33 mole) was weighed into theaddition funnel and added over a one-hour period. The reaction mixturewas heated at reflux for an additional three hours and then cooled. Theproduct was the derivative of E-100 in which all amine hydrogens hadbeen replaced with methylenephosphonic acid groups.

EXAMPLE 3

Ethyleneamine E-100* (12.5 g) and 12.5 g of deionized water were addedto a 500-ml round-bottom reaction flask as in Example 2 and heated to90° C. A 50% aqueous solution of3-chloro-2-hydroxypropyltrimethylammonium chloride (12.0, 0.032 mole)was weighed into the addition funnel and added over about a 10-minuteperiod. The reaction mixture was heated for an additional hour at 90° C.and cooled. Approximately 110 g of concentrated hydrochloric acidsolution and 28.5 g (0.035 mole) of phosphorous acid were added to thereaction flask and heated to reflux and maintained for one hour. Aqueous37% formaldehyde solution (24.5, 0.30 mole) was weighed into theaddition funnel and added over a one-hour period. The reaction mixturewas heated at reflux for an additional three hours and then cooled. Theproduct was the E-100 derivative in which ˜10% of the amine hydrogenshad been replaced with hydroxypropyltrimethylammonium chloride groups,the remainder being replaced with methylenephosphonic acid groups.

EXAMPLE 4 (Comparative)

An aqueous polymeric polyalkylenepolyamine (PAPA) solution (66.4 g of36%), prepared from ethyleneamine E-100 and ethylene dichloride, wasadded to a 500-ml round-bottom reaction flask equipped as in Example 1.Approximately 40 g of concentrated hydrochloric acid solution and 49.3 g(0.60 mole) of phosphorous acid were added to the reaction flask andheated to reflux and maintained for one hour. Aqueous 37% formaldehydesolution (51.1 g, 0.63 mole) was weighed into the addition funnel andadded over a one-hour period. The reaction mixture was heated at refluxfor an additional one and one-half hours and cooled. The product was thePAPA in which all amine hydrogens had been substituted withmethylenephosphonic acid groups.

EXAMPLE 5

The polymeric polyalkylenepolyamine used in Example 4 was modified byreacting ten mole percent of the available aminohydrogens with3-chloro-2-hydroxypropyltrimethylammonium chloirde in a similar manneras described in Example 3. The resultant reaction product was thenphosphonomethylated with phosphorus acid and formaldehyde in thepresence of hydrochloric acid. The product was the PAPA in which ˜10% ofthe amine hydrogens had been replaced withhydroxypropyltrimethylammonium chloride groups, the remainder beingreplaced with methylenephosphonic acid groups.

The products of Examples 1-5 were evaluated according to the followingscale inhibition test with respect to calcium carbonate: Several 50-mlsamples of a 0.02M CaCl₂ solution are placed in 4-ounce bottles. Tothese solutions is added the candidate inhibitor in variousconcentrations. Fifty-ml samples of a 0.04M sodium bicarbonate/0.96Msodium chloride solution are then added with stirring. A total hardnessdetermination is made on the mixture by adding excess standard EDTA to asample and back titrating with standard Mg⁺⁺ solution in the presence ofEriochrome Black T indicator. The samples are placed in an 80° C. ovenand 10-ml samples taken periodically from each bottle, filtered througha millipore filter, and the total hardness of the filtrates determinedby titration. A blank with no inhibitor is run in an identical manner.The relative inhibition effects are shown by determining the amount ofhardness (as soluble calcium) before and after heating for a 24-hourperiod. The amount of soluble calcium as a percent of that originallypresent is indicated as % inhibition.

Results of these tests are shown in Table I and compared with thephosphonated, but unquaternized amine. All products and comparative runswere made using a concentration of 10 ppm based on active acid.

                  TABLE I                                                         ______________________________________                                        Additive           % Inhibition                                               ______________________________________                                        EDA(CH.sub.2 PO.sub.3 H.sub.2).sub.4 (comp.)*                                                    41.8                                                       Product Ex. 1      41.8                                                       Product Ex. 2 (comp.)                                                                            43.4                                                       Product Ex. 3      49.9                                                       Product Ex. 4 (comp.)                                                                            35.0                                                       Product Ex. 5      38.1                                                       Blank (no additive)                                                                              12**                                                       ______________________________________                                         *This phosphonate is a commercially available compound sold for the           purpose of scale inhibition.                                                  **This indicates that 88% of the calcium had precipitated in the blank.  

In the above tests it can readily be seen that the methylenephosphonicacid derivatives which contain at least one quaternary group are atleast as good or better than the compounds containing only themethylenephosphonic group, including the derivative of EDA indicated asa commercially available scale inhibition compound. It should beunderstood that such compounds which contain only the quaternary groupsdo not exhibit any threshold effect, but that the methylenephosphonicacid group or its salt must be present for the effect to be obtained.

Reactants used to prepare the products of the invention are ammonia,alkyleneamines, polymeric amines and polyethyleneimines of differentmolecular weights, such as those from Cordova Chemical Company. Variousmetal and alkali metal salts, ammonium and amine salts and partial saltsof the methylenephosphonic acids and mixtures thereof can be utilized tomake the quaternized derivatives of the invention. It should be noted,however, that the quaternization of the amine preferably should precedethe phosphonomethylation and the making of any of themethylenephosphonic acid salts.

Almost any amine that contains reactive aminohydrogens can be utilizedto prepare the products. Thus for example, polyglycolamines,amidoamines, oxyalkylated amines, carboxymethylated amines,methylenesulfonated and hydroxypropylsulfonated amines,nitrogenheterocyclics, and the like can be employed as a reactant. Thepreferred products are those that have had the aminohydrogens fullyreplaced although some aminohydrogens can be left unreacted.

While the examples all show the use of the chloride form of thequaternary group, other halides, e.g. Br⁻ or I⁻, can be employed as thequaternized derivative. Thus, the quaternary salt could behydroxypropyltriethylammonium bromide, hydroxypropyltripropylammoniumiodide and the like.

We claim:
 1. Compounds having the formula ##STR3## wherein the A, B, Cand D substituents are independently selected from the group consistingof hydrogen, methylenephosphonic acid or salt thereof and2-hydroxy-3(trialkylammonium halide)propyl wherein each alkyl has from 1to 5 carbon atoms, n is 0 to 15, and wherein said substituents includeat least one methylenephosphonic acid group, or salt thereof, and atleast one 2-hydroxy-3(trialkylammonium halide)propyl group.
 2. Thecompound of claim 1 wherein n is 1 and one of A, B, C or D is a2-hydroxy-3(trialkylammonium halide)propyl group and the remainingsubstituents are methylenephosphonic acid groups.
 3. The compound ofclaim 1 wherein n is 0 and wherein one of A, B, or D is a2-hydroxy-3-(trialkylammonium halide)propyl group and the remaining twosubstitutents are methylenephosphonic acid groups or salts thereof. 4.The compound of claim 2 wherein the methylenephosphonic acid groups arepresent in the form of a salt of the acid.
 5. The compound of claim 3wherein the methylenephosphonic acid groups are present in the form of asalt of the acid.